U.S. patent application number 12/090324 was filed with the patent office on 2008-10-16 for strand guiding roller.
Invention is credited to Johann Poeppl, Guoxin Shan, Heinrich Thoene, Josef Watzinger, Franz Wimmer.
Application Number | 20080251229 12/090324 |
Document ID | / |
Family ID | 37547085 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080251229 |
Kind Code |
A1 |
Poeppl; Johann ; et
al. |
October 16, 2008 |
Strand Guiding Roller
Abstract
In the case of a strand guiding roller with at least one roller
shell and with hat least two supporting shafts, two supporting
shafts being respectively connected in a rotationally fixed manner
to a roller shell and each supporting shaft being rotatably
supported in a supporting bearing, to achieve a type of
construction that is simple and can withstand the high thermal and
mechanical loading that occurs, it is proposed that the roller
shell is connected in a rotationally fixed manner to the supporting
shafts carrying it on both sides by shrink-fit connections or by
press-fit connections.
Inventors: |
Poeppl; Johann;
(Kirchschlag, AT) ; Shan; Guoxin; (Linz, AT)
; Thoene; Heinrich; (Linz, AT) ; Watzinger;
Josef; (Reichenau, AT) ; Wimmer; Franz;
(Riedau, AT) |
Correspondence
Address: |
OSTROLENK FABER GERB & SOFFEN
1180 AVENUE OF THE AMERICAS
NEW YORK
NY
100368403
US
|
Family ID: |
37547085 |
Appl. No.: |
12/090324 |
Filed: |
October 2, 2006 |
PCT Filed: |
October 2, 2006 |
PCT NO: |
PCT/EP06/09541 |
371 Date: |
April 18, 2008 |
Current U.S.
Class: |
164/422 ;
148/559; 164/448 |
Current CPC
Class: |
B22D 11/1287
20130101 |
Class at
Publication: |
164/422 ;
164/448; 148/559 |
International
Class: |
B22D 11/128 20060101
B22D011/128; C21D 9/00 20060101 C21D009/00; B21B 39/00 20060101
B21B039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2005 |
AT |
A1717/05 |
Claims
1. A strand guiding roller comprising: at least one roller shell
having opposite first and second ends, a respective shaft recess
having an inner lateral surface in each end of the roller shell; a
respective supporting shaft connected in a rotationally fixed
manner at each end of the roller shell, a supporting bearing
rotatably supporting each supporting shaft; the roller shell being
connected in a rotationally fixed manner to the respective
supporting shafts carrying the roller shell on both ends by
shrink-fit connections or by press-fit connections; each supporting
shaft comprising at least one shaft stub having an outer lateral
surface which forms a shrink-fit connection or a press-fit
connection with the inner lateral surface of the recess in a roller
shell, wherein the shrink-fit connection or press-fit connection
has a length of shrink fit for which the ratio of the length of the
shrink fit to the diameter of the shaft is greater than 1.
2. The strand guiding roller as claimed in claim 1, comprising a
plurality of the roller shells arranged in a line in an axial
direction, two neighboring ones of the roller shells are
respectively connected in a rotationally fixed manner by a
respective one of the supporting shafts, and the one supporting
shaft is supported centrally by a respective one of the supporting
bearings.
3. The strand guiding roller as claimed in claim 1, further
comprising the roller shell having a cylindrical outer surface; at
least one coolant channel passing through the roller shell and the
at least one coolant channel is arranged radially inward from the
cylindrical outer surface of the roller shell; and substantially
radial feed and discharge lines for a cooling medium pass through
the shrink-fit connection between the supporting shaft and the
roller shell.
4. The strand guiding roller as claimed in claim 3, further
comprising a manifold sealing ring arranged between the roller
shell and the supporting shaft, the shaft forms with the roller
shell a coolant distributing line, into which the substantially
radial feed or discharge lines and the axially parallel coolant
channels run out, and the manifold sealing ring forming with the
roller shell and with the supporting shaft a rotationally fixed
shrink-fit connection or a press-fit connection.
5. The strand guiding roller as claimed in claim 2, further
comprising a coolant channel passing through the successive
supporting shafts and roller shells which alternate in the axial
direction.
6. The strand guiding roller as claimed in claim 1, further
comprising a cardan shaft connection of a driven strand guiding
roller having a connecting element connected in a rotationally
fixed manner to a respective supporting shaft supported centrally
on a supporting bearing by a shrink-fit connection or by a
press-fit connection.
7. The strand guiding roller as claimed in claim 1, wherein the
supporting bearings are movable bearings comprising rolling
bearings having rolling elements which compensate for operationally
induced axial displacements and alignment deviations (CARB
bearings).
8. The strand guiding roller as claimed in claim 3, wherein the at
least one coolant channel is arranged at a constant distance in
from the cylindrical outer surface of the roller shell.
9. The strand guiding roller as claimed in claim 5, wherein the
coolant channel is of a constant cross section and has a central
orientation in the axial direction of the roller.
Description
[0001] The invention relates to a strand guiding roller with at
least one roller shell and with at least two supporting shafts, two
supporting shafts being respectively connected in a rotationally
fixed manner to a roller shell and each supporting shaft being
rotatably supported in a supporting bearing.
[0002] A strand guiding roller of this type is already known from
DE-A 24 23 224. In the case of this multi-part strand guiding
roller, roller shells neighboring one another in the axial
direction are connected by a supporting shaft which is rotatably
supported in a journal bearing and engages with shaft stubs
directed away from one another in axial recesses of the neighboring
roller shells. A non-positive connection between the supporting
shaft and the respective roller shell takes place by means of a
screw connection between the two components and by interacting
radial supporting surfaces on the supporting shaft and on the
roller shell, whereby additional securement against release during
operation of the plant is achieved. However, this design solution
has not proven successful in practice, since this way of holding
the components together does not withstand the rigours of
metallurgical plant operation.
[0003] It is already known from WO 02/02253 A1 to form driver
rollers in a strip casting plant from a roller shell and two
supporting shafts, wherein the two supporting shafts, lying
opposite one another, protrude into the roller shell and are
screwed at their extreme ends to the roller shell (FIG. 6). The
tightening screws are at the same time used as closure elements of
the coolant lines.
[0004] A one-part strand guiding roller in which a roller shell is
undetachably connected to two supporting shafts by a peripheral
welded connection is known from DE-A 28 40 902. The roller shell is
coated with an abrasion-resistant, non-corroding protective layer.
Damage to individual components of a strand guiding roller usually
result in their total loss and in high spare part costs.
[0005] The use of a weld for the connection of the roller shell and
the supporting shaft is specifically not practicable for multi-part
strand guiding rollers, since split bearings should necessarily be
used for these. Such a centrally mounted strand guiding roller, in
which a supporting shaft carrying a supporting bearing is connected
to adjoining roller shells by welded connections is known from DE-A
32 28 190.
[0006] In the case of conventional peripherally cooled strand
guiding rollers, as are already known for example from EP 0 543 531
A1 or AT 412 851 B, the coolant is conducted through coolant
channels predominantly arranged radially or inclined in relation to
the axis of rotation of the roller from the center of the roller to
the periphery of the strand guiding roller, distributed there by
way of ring lines, taken close to the surface of the roller shell
through coolant channels aligned parallel to the roller axis and in
an analogous way collected again and returned to the center. To
make it easy to produce the coolant conducting system and the ring
lines and seal them tightly with respect to the outside, sealing
elements in the form of rings or plugs are usually screwed or
welded to the end faces of the roller shell. Owing to the high
thermal and material-related loads in the strand guiding roller,
these sealing methods are complex, very sensitive and susceptible
to faults.
[0007] It is also known in the case of strand guiding rollers with
a continuous core shaft to fasten multi-layered roller shells in a
rotationally fixed and detachable manner on the core shaft, for
example by a feather key connection. The multi-layered structure of
the roller shell is obtained by individual cylindrical sleeves,
which are connected in a rotationally fixed manner by a full-area
shrink-fit connection of the lateral surfaces of the cylinders
lying opposite one another. The easy-to-produce coolant channels
are located at the contact surfaces of the cylindrical sleeves (WO
2005/016578; WO 02/02253).
[0008] The present invention aims to avoid these difficulties and
disadvantages and sets out to propose a strand guiding roller that
comprises a number of easy-to-produce components which are
connected to one another in such a way that the connection
withstands the intensive thermal and mechanical loads during the
casting operation, comprises components that are easy to produce
and makes it possible for expensive components, such as preferably
the roller shells and bearing housings, to be disassembled and
possibly reused.
[0009] This object is achieved according to the invention by the
roller shell being connected in a rotationally fixed manner to the
supporting shafts carrying it on both sides by shrink-fit
connections or by press-fit connections.
[0010] The intermediate supporting type of bearing takes place in
principle on constrictions in the rollers, which takes place by
means of the supporting shafts of smaller diameter shrink-fitted
into the roller shells.
[0011] The shrink-fit or press-fit connection is designed such that
stationary and non-stationary roller loads and drive torques
occurring in the case of driven strand guiding rollers can be
reliably transmitted and sealing functions for the coolant
circulation are reliably ensured. The design of the shrink-fit or
press-fit connection takes into account specific, operationally
customary load cases, such as [0012] continuous strand take-off
with rotating strand guiding rollers, [0013] stopped strand with
stationary strand guiding rollers, [0014] roller cooling on the
outside and on the inside, [0015] roller cooling only on the
outside or only on the inside, [0016] total failure of the roller
cooling caused by a fault.
[0017] Even in the worst case, that the shrink-fit or press-fit
connection loses load-bearing capacity as result of thermal
influence, adequate bending and rolling moment transmission and
sealing function must still be ensured. In the case of strand
guiding rollers with a roller diameter of 150 mm to 200 mm, this
means a shrinkage oversize of 0.2 to 0.5 mm and, in the case of a
greater roller diameter of 200 mm to 250 mm, a shrinkage oversize
of 0.25 to 0.4 mm. As an approximate guide for fixing the length of
the shrink fit, the ratio of the length of the shrink fit to the
diameter of the shaft stub is greater than 1.
[0018] In comparison with perforated solid-body rollers, the
shrink-fit connection results in lower notch stresses, thereby
reducing the risk of rupture of the strand guiding roller. It is
also possible to use material of higher strength for the lighter
supporting shafts, allowing a very specific, and consequently
economical, increase in strength to be achieved.
[0019] The described subassembly arrangement with shrink-fit or
press-fit connection gives rise overall to the following
advantages: [0020] The simple plug-in type of construction permits
easy assembly of the long strand guiding rollers and low-cost
production of the individual components. [0021] In the case of
multi-part strand guiding rollers, no split intermediate supporting
bearings are necessary. [0022] The particularly cost-effective
production makes the strand guiding roller suitable as an
inexpensive disposable roller. [0023] Alternatively, however,
partial reuse of the strand guiding roller is also possible,
specifically of the roller shell with the peripheral cooling
system, and the bearing housings can also be reused. This is
carried out by simple destructive disassembly, for example by a
severing cut through the shaft stub of the supporting shaft. [0024]
The sealing of the coolant passageways can take place largely
without sensitive, synthetic sealing elements and without
welds.
[0025] Each supporting shaft comprises at least one shaft stub, the
outer lateral surface of which forms a shrink-fit connection or
press-fit connection with an inner lateral-surface of a recess in a
roller shell.
[0026] The basic structure of the components forming the shrink-fit
or press-fit connection, both at the end regions of the strand
guiding roller and in the regions between neighboring roller
shells, is expediently the same. Accordingly, with a number of
roller shells arranged in line in the axial direction, two
neighboring roller shells are respectively connected in a
rotationally fixed manner by a supporting shaft supported centrally
by a supporting bearing.
[0027] The strand guiding rollers are equipped with internal
cooling, two embodiments being particularly expedient:
[0028] According to one possible embodiment of the roller cooling,
the roller shell is passed through by at least one coolant channel
and this coolant channel is arranged at a constant distance from
the cylindrical outer surface of the roller shell. In this case,
the coolant channel forms, for example, a peripheral annular space.
The roller shell is preferably passed through by a multiplicity of
coolant channels, which are arranged at a constant distance from
the cylindrical outer surface of the roller shell. The
substantially radial feed and discharge lines for the cooling
medium pass through the shrink-fit connection between the
supporting shaft and the roller shell.
[0029] The feed and discharge lines may also be arranged inclined
in relation to the axis of rotation of the strand guiding
roller.
[0030] According to a refinement of the coolant circulating system
that is simple in production engineering terms, arranged between
the roller shell and the supporting shaft is a manifold sealing
ring, which forms with the roller shell a coolant distributing
line, into which the substantially radial feed or discharge lines
and axially parallel coolant channels run out, and this manifold
sealing ring forming with the roller shell and with the supporting
shaft a rotationally fixed shrink-fit connection or a press-fit
connection.
[0031] With this peripheral cooling, a long service life of the
strand guiding roller is achieved as a result of the early removal
of heat from the roller shell. Furthermore, the intensive roller
shell cooling makes it possible for the continuous casting plant to
be operated in a dry mode and allows continuous slabs, in
particular thin continuous slabs, to be transported at higher
temperature by the strand guidance of the continuous casting
plant.
[0032] According to a further possible embodiment of the roller
cooling, a coolant channel of a constant cross section and a
central orientation in the axial direction passes through the
alternately successive supporting shafts and roller shells. This
axial cooling is particularly distinguished by its simplicity and
inexpensive type of construction.
[0033] In the case of both embodiments of the roller cooling, the
shrink-fit or press-fit connection means that there are no coolant
leakages. It is possible to dispense with special seals within the
strand guiding roller, since the sealing is produced by the
shrink-fit connection.
[0034] In the case of a driven strand guiding roller, the described
shrink-fit or press-fit connection can be used for the connection
to the drive elements, in that a cardan shaft connection of a
driven strand guiding roller is connected in a rotationally fixed
manner to a supporting shaft supported centrally on a supporting
bearing by a shrink-fit connection or by a press-fit
connection.
[0035] The sealing of the coolant channels and coolant distributing
lines by means of manifold sealing rings introduced into the roller
shell by shrink-fit or press-fit connection obviate the need for
sensitive independent sealing elements and welded connections.
[0036] In particular, the supporting bearings of the strand guiding
roller that are formed as movable bearings are formed by rolling
bearings, the rolling elements of which can compensate for
operationally induced axial displacements and alignment deviations.
Toroidal bearings, as are described for example also in the German
utility model specification DE 200 21 514 U1, may be used for
example for this purpose.
[0037] Further advantages and features of the present invention
emerge from the following description of non-restrictive exemplary
embodiments, reference being made to the accompanying figures, in
which:
[0038] FIG. 1 shows a strand guiding roller according to the
invention with two roller shells and peripheral roller shell
cooling,
[0039] FIG. 2 shows a strand guiding roller according to the
invention with three roller shells and central roller cooling,
[0040] FIG. 3 shows a cross section through the strand guiding
roller with a representation of the coolant feed along the
sectional line A-A in FIG. 1,
[0041] FIG. 4 shows a partial section of the strand guiding roller
with inclusion of a manifold sealing ring for passing the coolant
through.
[0042] The representations in the figures schematically show strand
guiding rollers according to the invention, such as for example
those suitable for use in a strand guide of a continuous casting
plant for producing metal strands of great width with a cross
section of slabs or thin slabs. Components that are the same or
have the same effect in different embodiments are identified by the
same designations.
[0043] The non-driven, two-part strand guiding roller represented
in a longitudinal section in FIG. 1 comprises two roller shells 1,
2 and three supporting shafts 4, 5, 6, the supporting shafts being
rotatably supported in supporting bearings 8, 9, 10. The supporting
shaft 5 arranged between two roller shells 1, 2 ends in two shaft
stubs 12, 13, which are directed away from one another in the axial
direction and protrude into cylindrical recesses 14, 15 of the
neighboring roller shells 1, 2. The non-positive connection between
the shaft stub 12, 13 and the roller shell 1, 2 is produced by a
shrink-fit connection or a press-fit connection, which takes into
account the prevailing thermal and mechanical loads during the
transportation of a steel strand through the strand guide. Two
supporting shafts 4, 5 carrying the roller shells 1, 2 at the ends
of the strand guiding roller respectively have only one shaft stub
16, 17, which stubs are fitted in recesses of the roller shells 1,
2, forming a shrink-fit or press-fit connection.
[0044] The strand guiding roller is equipped with internal cooling,
formed as peripheral cooling and represented in FIGS. 1 and 3. The
introduction of coolant into the supporting shaft 4 takes place
through a rotary lead-in 21 coupled onto the end. The supporting
shaft 4 has a central coolant channel 22, 22a, from which a number
of radial branch lines 23, 23a, 23b, 23c lead away from the region
of the shaft stub 16 to the roller shell 1 and run out there in an
annular space 24 with sickle-shaped widenings 25a, 25b, 25c. From
these sickle-shaped widenings, coolant lines 26, 26a, 26b, 26c lead
under the surface of the shell, at a small distance from it and
distributed uniformly over the circumference of the roller shell 1,
parallel to the axis of rotation of the strand guiding roller, with
a repeated reversal in direction being provided. In the region of
the shaft stub 12 of the supporting shaft 5, the coolant lines 26
run out again in sickle-shaped widenings of an annular space, from
which radial branch lines lead to the central coolant channel 22b
in the shaft stub 12 of the supporting shaft 5. In the region of
the shaft stub 13, the passing through of the coolant is repeated
for the roller shell 2 in a way analogous to the described way in
which the coolant passes through in the roller shell 1. This
arrangement is repeated furthermore according to the number of
roller shells from which a multi-part strand guiding roller is
formed. The central coolant channel runs out in a rotary transition
lead-in 21a, through which the coolant flowing through the strand
guiding roller is led away again. The coolant lines are routed such
that, in the region of the shrink-fit connection, they run from the
supporting shaft into the roller shell and back, so that the tight
shrink-fit connection acts at the same time as a seal against
coolant leakages.
[0045] FIG. 2 schematically represents a three-part strand guiding
roller, which comprises three roller shells 1, 2, 3, supporting
shafts 4, 5, 6 carrying these roller shells and supporting bearings
8, 9, 10, 11 rotatably supporting the supporting shafts. As already
described with respect to the strand guiding roller according to
FIG. 1, the roller shells and the supporting shafts are
non-positively connected by a shrink-fit or press-fit connection.
The passing through of the coolant takes place through a central
coolant channel 28, which passes in the axial direction through the
successive supporting shafts and roller jackets. On the input side
and on the output side of the coolant channel, rotary lead-throughs
21 for feeding in and leading away the coolant are provided, only
the rotary lead-through for the feeding in of the coolant being
represented. The shrink-fit connections between the roller shells
and the supporting shafts seal the transitions of the central
coolant channel between the roller shell and the supporting shafts
against losses from leakage with respect to the outside.
[0046] FIG. 1 shows a multi-part driven strand guiding roller in
which the outer supporting shaft 6 has two shaft stubs 17, 30. The
shaft stub 17 is connected to the roller shell 2 by a shrink-fit
connection and the shaft stub 30 protrudes into a connecting
element 31 of a cardan drive shaft, which is likewise connected by
a shrink-fit connection to the shaft stub 30.
[0047] In FIG. 4, a further embodiment of a strand guiding roller
with peripheral cooling is represented in a partial section and
shows the coolant return from the coolant lines 26 passing through
the roller shell 1 in the axial direction into the coolant channel
22b arranged centrally in the shaft stub 12. All the coolant lines
26, of a parallel orientation, run out into a coolant distributing
line 33, which is formed by a peripheral ring line and the walls of
which are formed by the roller shell 1 and a manifold sealing ring
34. Just a few radially aligned discharge lines 23a connect the
ring lines 33 to the coolant channel 22b. In the same way, at a
different location, the feeding in of the coolant takes place
through coolant distributing lines arranged in an analogous
way.
[0048] Altogether, FIG. 4 shows four possible design variants of
the manifold sealing ring 34, 35, 36, 37.
[0049] The manifold sealing ring 34 is pressed into the roller
jacket 1 and forms with it a rotationally fixed shrink-fit or
press-fit connection. Equally, the manifold sealing ring 34 is
shrink-fitted together with the roller shell 1 on the shaft stub
12.
* * * * *